Biomass Yield and Quality of Fodder From Selected Varieties of Lablab in Nandi South Sub-county, Kenya

Abstract

Inadequate feeds, both in quality and quantity, is the main challenge facing livestock production in Kenya. Use of concentrate feeds (especially high protein) to enrich low quality fodder is mostly beyond the reach of small-scale farmers due to high cost and as such, cheaper alternative supplements such as lablab bean forage are needed. The main objective of this study was to determine biomass yield and nutritive value of both fresh and conserved fodder from eight lablab varieties. The specific objectives were; to determine biomass production and nutritive value of fodder from selected Lablab varieties and to evaluate the effect of conservation as hay or silage on the quality of lablab fodder. The varieties; DL 1002, Ngwara Nyeupe, Echo-Cream, Black Rongai, Eldoret-Kitale-Cream, Eldoret-Kitale-Black 1, Brown Rongai and Eldoret-Kitale-Black 2 were assessed in three sites of Nandi South sub County, Kenya. Eight lablab varieties, each replicated four times per site, were established in four farms in each site in a randomized complete block design and harvested after attaining 50% flowering. Data on biomass yields, nutrient content and invitro-dry matter digestibility of fresh and conserved forages was collected for all the varieties. Biomass yield differed significantly among the eight lablab varieties ranging from 5.6 to 12.6 t DM/ha across the three sites. Brown Rongai had the highest biomass yield of 12.6 t DM/ha while DL1002 recorded lowest yield of 5.6 t DM/ha. Crude protein content of lablab varied significantly between varieties and sites, ranging from 19.6 to 23.9 g/100g DM. Eldo-Kt-Cream and Black Rongai varieties had the highest crude protein content of 23.9 g/100g DM and 23.7 g/100g DM across the three sites. Neutral detergent fibre (NDF) ranged from 44.4 to 48.6 g/100g DM acid detergent fibre (ADF) ranged from 31.6 to 35.7 g/100g DM while acid detergent lignin (ADL) from 9.0 to 11.9 g/100g DM for all the varieties of lablab across the three sites. Variety DL1002 had the highest NDF content of 48.6 g/100g DM across the three sites. The highest ADF was recorded for Eldoret-Kitale-Black2 variety with 35.9 g/100g DM, whereas highest acid detergent lignin of 11.7 g/100g DM was recorded for DL1002 variety. Invitro dry matter digestibility (IVDMD) varied significantly between varieties and sites. It ranged from 67.6 to 75.7 g/100g DM among the varieties across the three sites. Eldo Kt-cream and Black Rongai varieties had the highest IVDMD of 75.7 and 74.4 g/100g DM across the three sites respectively. The pH of the lablab silage ranged from 4.3 to 4.8 while total ammonia nitrogen content ranged from 27 to 41 g/100g. On-farm conservation of lablab as hay led to a decline of 4.8 g/100g DM of crude protein and 1.9 g/100g DM in dry matter digestibility while conservation as silage led to a decline of 6.0 g/100g CP DM and an increase of IVDMD by 4.5

g/100g DM. It was concluded that Eldoret-Kitale-Cream and Black Rongai varieties of lablab exhibited superior dry matter yield, crude protein content and low fibre fractions compared to the others signifying their potential for recommendation as alternative low quality fodder supplement among the small-scale farmers. Conservation of lablab fodder as silage resulted in a superior quality forage with higher IVDMD and crude protein content and low fibre fractions.